Valve tilting means for a burner fuel control system or the like



c. WANTZ FETAL 3,167,250 VALVE TILTING MEANS FOR A BURNER FUEL. CONTROLSYSTEM OR THE LIKE Filed Nov. 17, 1961 4 Sheets-Sheet l m m a A u n m mT Q Q 6 m m mv v I J/ mm m m mm wmm mm ww g 1 Hm I M O rlllalk CCDH mmmm Y B I\ rlr l\ mm H MN I lllll l I Wm N mm vm omoooooo mm vm m: m9 5mm NJ m9 vm mo r. l I l |||x l I ll Om Jan. 26, 1965 ATTORNEY Jan. 26,1965 c. WANTZ ETAL 3,167,250

VALVE TILTING MEANS FOR A BURNER FUEL CONTROL SYSTEM OR THE LIKE FiledNov. 17. 1961 4 Sheets-Sheet 2 FIG-2A INVENTORS CLARENCE WANTZ CHARLESD. BRANSON ROY c. DEM! ATTORNEY Jan. 26, 1965 c. WANTZ ETAL 3,167,250

VALVE TILTING MEANS FOR UR FUEL.

CONTROL SYSTEM OR LI Filed Nov. 17, 1961 4 Sheets-Sheet 3 BY ROY C. Ml

ATTORNEY Jan. 26, 1965 c. WANTZ ETAL VALVE TILTING MEANS FOR A BURNERFUEL CONTROL SYSTEM OR THE LIKE 4 Sheets-Sheet 4 Filed Nov. 17, 1961FIG-l3 INVENTORS CLARENCE WANTZ CHARLES D. BRANSON ROY C. DEM] ATTORNEYUnited States Patent 3,167,250 VALVE TILTING MEANS FUR A BUR FUELCONTRQI. SYSTEM OR THE LIKE Clarence Wantz, Charles I). Branson, and RoyC. Demi,

all of Greensburg, Pa, assignors to Robertshaw Controls Company,Richmond, Va, a corporation of Delaware Filed Nov. 17, 1961, Ser. No.152,998 14 Claims. (Cl. 236-468) This invention relates to systems forcontrolling the flow of fuel to burners and the like, such as a domesticgas oven burner to maintain a preselected temperature within the oven.This invention also relates to improved parts for such systems and thelike.

Heretofore, the temperature of an oven or the like has been controlledby utilizing a control valve that thermostatically throttles the flow offuel to the oven burner in response to the temperature of the oven.However, such a control valve is normally provided with a by-pass sothat when the thermostatic valve is closed a sufficient amount of fuelis permitted to flow to the oven burner so that the gas will burn at theoven burner.

It has been found that this small by-pass flame burn ing at the mainoven burner, when the main thermostatic valve is closed, heats the ovento such a temperature that the oven temperature cannot be maintainedbelow 300 F., whereby there is no means for maintaining food and thelike in the oven at a low warming temperature that will not cook thefood.

However, according to the teachings of this invention, an improved fuelcontrol system is provided for maintaining the oven temperature at aselected low warming and non-cooking temperature as well as providing asuitable control for maintaining the oven at normal cooking temperaturesby utilizing a single main oven burner.

Accordingly, it is an object of this invention to provide an improvedfuel control system having one or more of the novel features set forthabove or hereinafter shown or described.

Another object of this invention is to provide an improved valveconstruction for such a fuel control system or the like.

A further object of this invention is to provide improved parts for sucha valve construction or the like.

Other objects, uses and advantages of this invention are apparent from areading of this description which proceeds with reference to theaccompanying drawings forming a part thereof and wherein:

FIGURE 1 is a fragmentary, schematic view illustrating the fuel controlsystem ofthis invention.

FIGURE 2 is an enlarged, axial, cross-sectional view illustrating theimproved valve construction of this invention utilized in the fuelcontrol system of FIGURE 1.

FIGURE 2A is a fragmentary view similar to FIGURE 2 illustrating amodification of one of the valve members of the valve construction ofFIGURE 2.

FIGURE 3 is a fragmentary, cross-sectional view of the valveconstruction illustrated in FIGURE 2 and is taken on line 3-3 thereof.

FIGURE 4 is an end view of the valve construction illustrated in FIGURE2 and is taken substantially on line 4-4 thereof.

FIGURE 5 is a cross-sectional view of the valve construction illustratedin FIGURE 2 and is taken on line 5-5 thereof.

FIGURE 6 is a fragmentary, cross-sectional view taken on line 66 ofFIGURE 5.

' FIGURE 7 is a fragmentary, cross-sectional view taken on line 7-7 ofFIGURE 6 and illustrating the opening and closing movements of a valvemember of the valve construction of FIGURE 2.

ice

FIGURE 8 is a side view of one of the valve members of the valveconstruction of FIGURE 2.

FIGURE 9 is a cross-sectional view of the valve member of FIGURE 8 andis taken on line 99 thereof.

FIGURE 10 is a view similar to FIGURE 9 and is a cross-sectional viewtaken on line 1010 of FIGURE 8.

FIGURES ll-l5 are schematic views illustrating the position of the cockvalve of FIGURE 8 at various temperature settings of the valveconstruction of FIGURE 2.

While the valve construction of this invention and the improved partsthereof are illustrated as being incorporated in the fuel control systemof this invention, it is to be undertsood that these features of thisinvention could be utilized in other systems, as desired.

' Therefore, this invention is not to be limited to only the embodimentsthereof illustrated in the drawings, because the drawings are merelyutilized to illustrate one of the wide variety of uses of thisinvention.

Referring now to FIGURE 1, the fuel control system of this invention isgenerally indicated by the reference numeral 20 and is adapted toselectively maintain the temperature in the oven 21 at any selectedtemperature through a range of low warming and non-cooking temperaturesas well as through a range of high cooking temperatures by utilizing asingle main oven burner 22 in a manner hereinafter described.

For example, the fuel control system 20 of this invention is adapted tomaintain the temperature of the oven 21 at any selected temperature fromF. to 550 F., while conventional fuel control systems are not adapted tomaintain the temperature of a particular oven below approximately 300 F.

The fuel control system 20 comprises a source of gas or other fuelmaintained in a manifold 23, the manifold 23 being interconnected to acontinuously burning standby pilot burner 24 by a conduit or passagemeans 25.

The passage means 25 has a suitable filter and adjusting valvearrangement 26 to maintain the flame 27 of the standby pilot burner 24at the proper level, the standby pilot burner 24 being adapted to ignitefuel issuing from the main oven burner 22 and a controlled pilot burner28 in a manner hereinafter described.

A valve construction 29 of this invention has an inlet 30 thereofinterconnected to the manifold or source of fuel 23 and an outlet 31interconnected to a main conduit or passage means 32 leading to the mainoven burner 22, the passage means 32 having a safety valve means 33disposed therein and controlling the flow of fuel to the main ovenburner 22 in a manner hereinafter described.

The safety valve 33 is adapted to open and interconnect the main passagemeans 32 to the main oven burner 22 when a flame 34 exists at thecontrolled pilot burner 28 the flame 34 heating mercury or the like in asensing bulb 35 which causes a bellows arrangement 36 to expand and opena valve member 37 of the safety valve means 33 to interconnect the inlet38 thereof with the outlet 39, the outlet 39 having an adjustableorifice device therein and projecting into an opening formed in the end40 of the main oven burner 22.

The valve member 37 of the safety valve 33 is normally urged against thevalve seat 41 by a compression spring 42, the valve member 37 having astem 43 engaging a lever 44 pivotally mounted to a bracket 45 by afulcrum member 46. The other end of the lever 44 is engaged by a lever47 pivotally mounted to the bracket 45 by a fulcrum member 48, the lever47 threadedly carrying an adjusting screw 49 passing through a suitableaperture in the lever 44 and disposed within a compression spring 50disposed between the levers 47 and 44 and tending to maintain the levers44 and 47 in the position illustrated.

In this manner, when a flame 34 exists at the coninside the valve member56.

trolled pilot burner 28 in a manner hereinafter dev scribed, themercuryin the bulb 35 heats up and vaporizes' Y causing the bellows 36 toexpand whereby the lever 47 is pivoted downwardly about thesfulcrummeans 48 and causes the lever 44 to pivot'upwardly about the fulcrum'means 46,, the pivoting lever 44 carrying the 'valvemember 37 therewithaway fromthe valve seat 41- to interconnect the main passage means 32with the main oven burner 22 so thatfuelcan flow to the main oven burnerI 22 and be ignited by the standby pilot burner 24. Conversely, whenthejflame 34 ceases to exist .at the controlled, pilot burner 28, the.mercury in the bulb 35 condenses Wherebythe bellows 36 contracts tocause the levers 47 and 44 to be pivoted back to the positionillustrated .in FIGURE 1 by the force of a compression spring 42 closingthe valve member 37 totprevent fuel from being supplied to the mainjovenburner 22.

The valve construction 29 is adapted to control the I scribed. 3

As illustrated in FIGURE 2, the valve construction 29 includes a housing51 formedfrom two housing members 52 and 53 suitably interconnectedtogetherbyebolts I 54 or the like, the housing 51 havingta cavity 55formed therein and interconnected to the aforementioned inlet .30 andoutlet 31.

A. rotatable cock valve member 56' is disposed in a 'flowof fuel to.thetmain' passage means 32 and to the 4:

controlled pilot burner 28 in a manner now to be de-' tapering portion57 of the cavity 55 and is adapted to' vcontrol communicationbetween'the inlet and: the

cavity in a manner hereinafter described.

The valve member 56 has a longitudinal bore 58 pass-v ing therethroughand so constructed and; arranged that the bore 58 defines a pair ofstepped shoulders;59 and,

An adjusting stem 61 is disposed the shoulder 59 to frictionallyinterconnect the stem 61 the valve member 56will' be imparted to'thestem 61.

in the bore v5 8 and has 7 a tapering surface 62 cooperable with thecorner 63 of an inwardly bent tab 80 that is 'slidably disposed in aslot 81(FIGURE 4, of the valve member-5 6, the sleeve 79 being suitablysplined to acontrol knob 82 having a removable plate 83 spring-pressedtherein.

. A drive ring 84-is 'disposedbetween the housing 51 and the covermember 72 and has a pair of inwardly directed opposed tab means'85slidably' disposed in opposed slots 86 formed at the right end of thesleeve 79.

The driverring 84 has va pair of perpendicularly bent outer tabmeans 87respectively receivable in slots 88 posed; against ;the,drive 'n'ngy84and the other end 93 0 thereof disposed against a retainer ring 94carried by the housing51 and abutting the valve member 56 wherebythecompression spring91holds the valve member 56 into wedging relationwith the tapering portion 57 of the cavity '55 and normally holds thedrive ring 84 against the cover member 72whereby the tabs 87'. of thedrive ring 84 project through the slots 88 of thecover member 72 toprevent rotational movement of the control knob 82 and thereby preventrotational movement of the valvemember56. I f

However, when it is desired to rotate the valve member 56 theloperatoraxially Ipushes thecontrol knob 82 to the right whereby'the sleeve 79carriestthe drive ring 84 to the right in opposition to the force of'thecompression spring 91 until the tab means 87 of the drive ring 84 havecleared the slots: 88 of'the cover. member 72 to permit the control knob82 to be rotated. Rotational movement of the controlknob 82' causes thesleeve 79 to rotate in unison there- 7 with whereby the tab means 80 ofthe sleeve 79 and the .to the valve member 56 so that rotationalmovement of 7.

In particular, a retaining ring 64 is disposed in'an annular groove65'formed in the stem 61 and is retained thereon by a split ring 66 wherebyone end 67 of a compression spring 68 bears against the retaining ring-64 and has the other end69 thereof disposed'against a're-,

taining ring 70 compacting a seal 71' against the shoulder 60'ofthevalve member 56 to prevent fuel leakage between the stem 61 andvalve member 56.; I

In this manner, the compression spring 68 tends to urge thestem 61 tothe left as viewed in the drawings to frictionally wedge the taperingsurface 62 of the stem 61 into driving relation with the corner 63 ofthe shoulder 59 of the valve member 56 whereby rotational movement 1unison therewith.

However, the stem 61 can be disengaged from the,

of the valve member 56 causes the stern61- to rotate in valve member 56byaxially moving the stem 61 to the I 1 right in opposition to the forceof the compression spring 68 whereby the tapering surface 62of the'stem61 will-i'i be disengaged from the corner 63 of the shoulder 59 of thevalve member 56 for the purpose hereinafter deseribedx The valve member56 is adapted to be rotated in the housing 51in the following manner. a

A cover member 72,"FIGURES 2, 3 and 4, has an outwardly directed annularflange 73 provided with 0pv in the off'position.

As i-llustratedfin FIGURESS-IO, therotatable valve. -member 56 hasafirst recess -9S, f ormed"therein and extending substantially aroundtheouter periphery thereof, the recess 95-being interconnected to the bore58 of the tab? means and 89 ofthe drive ring 84 cause the valvememberi56 to rotate in unison with' the sleeve 79, the stem 61 rotatinginrunison' With the valve member 56 because 1 of the aforementionedfrictional drive relation between the stem 61 and valve member'56. V v yTherefore, once the control knob 82 has been axially pushed to'the rightto clear the tab means 87 from the slots 88 and has been slightlyrotated, the tab means 87 of the drive ring 84' are out of register withthe slots 88 of the cover member 72 so that the control knob 82 is heldin its pushed in position; and can be'manually rotated to thedesired"positionwithout exerting force in opposition to .the forceof thecompression spring 92, the tab means 87 .of the drive ring 84registering with the-slotmean's-88 of the cover member 72 whenthecontrol knob is disposed valve member 56 by a pairof spaced bores '96and 97.

The recess in the valve member-56' is so constructed and arranged, thatthe sameis disposed in aligned relation'with the inlet 30, of'the valveconstruction 29 where- V by the'valve member 56 closes off communicationbetween posed cars 74 that are adapted to be secured to the housing 51by threaded members 75, the cover member 72 portion 76 splined to asplit collar 77 by a tab means 78 of the cover 72 e a l 8' a The splitcollar 77 issplined in any suitable to a generally angular bezel 77a. 7

I having an outwardly directed substantially cylindrical manner Arotatable sleeve 79'is telescopically disposed in the Z cylindricalportion 76 of the cover member 72.. and has a the inlet 38 and thecavity55 when the valve member 56 is in the off position illustrated inFIGURES'Z and 11 and 'is adapted to progressively increase the degree ofcommunication between theinlet-30 and the cavity 55 as the valve member56- is rotated in the counterclockwise di- "rec tion as illustrated inFIGURES 11-15.

A pair of rotationally aligned slots 98 and 99 are also formed in thevalve member 56 as illustrated in FIG- URE 10, the slots 98. and 99being respectively interconnected to the'bore 58 of the valve member56-for a purpose hereinafter described. 1 I V T he housingSl is soconstructed and arranged that the same defines a first annularvalve'seat 100 in the cavity 55 between the inlet and outlet" 31 anddownstream from the valve member 56 previously described, the valve seat100 encompassing a second and smaller annular valve Seat 101 oifset fromthe center of the valve seat 100 and disposed in the same plane with thevalve seat 100. The valve seat 101 is interrupted by a passage means 102leading to the exterior of the housing 51 and being interconnected tothe pilot burner 28 by a conduit or passage means 103. A bypass passagemeans 104 is formed in the housing 51 and is interconnected to thecontrolled pilot passage means 102 and to the cavity 55 of the housing51 at a point upstream from the valve seats 100 and 101 for a purposehereinafter described, the bypass passage means 104 being aligned withthe slots 98 and 99 of the valve member 56 whereby the valve member 56selectively opens and closes the bypass means 104 to the bore in thevalve member 56 for a purpose hereinafter described.

A bellows construction 105 is disposed in thecavity of the housing 51and has one wall 106 thereof interconnected to a retainer 107 secured tothe housing 51 by a nut 108, the other wall 109 of the bellowsconstruction 105 carrying a retainer 110 provided with a threaded bore111.

The interior of the bellows construction 105 is interconnected to atemperature-sensing bulb 112 by a conduit or passage means 113, the bulb112 being disposed in the "oven '21 and causing the bellows construction105 toexpand or contract in relation to the temperature of the oven 21in a manner well known in the art.

A shaft 114 carries a pin 115 at the end 116 thereof, the pin 115 beingslidably disposed in a pair of opposed slots 117 formed in the right endof the stem 61 previously described. The other end 118 of the shaft 114is externally threaded and is disposed in threaded relation with thebore 111 of the retainer 110 of the bellows construction 105.

A bi-metal, spring disc 119 is telescopically disposed 'on the shaft 114and is retained in a recess 120 thereof,

the bi-metal disc 119 bearing against a valve member 121 s'lidably androckably disposed on the shaft 114. The valve member 121 is adapted toopen and close the valve seats 100 and 101 previously described.

A compression spring 122 has one end 123 thereof engaging a retainer 124disposed on the retainer 110 of the bellows construction 105 andabutting an annular flange 125 of the retainer 110, the other end 126 ofthe compression spring 122 bearing against a retainer 127 which isslidably disposed on the shaft 114 and compacts a spacer 128 against thevalve member 121.

In this manner, rotational movement of the valve member 56 in acounterclockwise direction causes the shaft 114 to rotate and, throughthe threaded relation of the end 118 thereof with the retainer 110,causes the shaft 114 to axially advance to the right whereby thebi-metal disc 119 carries the valve member 121 away from the .valveseats 100 and 101 in opposition to the force of the compression spring122, the bi-metal disc 119 varying the position of the valve member 121on the shaft 114 in response to ambient temperature changes.

For example, a setting of 400 degrees'F. by the control knob 82 willposition the valve member 121 relative to the seats 100 and 101 apre-set distance when the oven is at 70 degrees F. and the atmospheresurrounding the bellows construction 105 is 70 degrees F. However, forsuch a temperature setting of 400 degrees F. for the control knob 82 andthe oven at 70 degrees F. and with the atmosphere surrounding thebellows construction dropping to degrees F., the valve member 121 wouldbe at a greater distance from the seats 100 and 101 because of movementof the wall 105 of the bellows construction 105 to the right in FIGURE 2because of the drop of ambient temperature surrounding the bellowsconstruction 105 were it not for the bi-metallic disc 119 whichcompensates for the change in ambient temperature at the bellowsconstruction 105 and changes the shape to be flatter so that the spring122 moves the valve member 121 back to the left a distance correspondingto movement of the wall 109 of the bellows 105 to the right wherebyregardless of the ambient temperature at the bellows construction 105,the valve member 121 will be at the desired distance from the seats 100and 101 at any particular setting of the control knob 82 at a particulartemperature sensed by the bulb 112 because of the bimetallic disc 119.

When the valve member 121 is moved away from the valve seats 100 and 101and the valve member 56 interconnects the inlet 30 with the cavity 55through the recess thereof, fuel from the manifold 23 is adapted to flowout of the valve seat to the passage means 32 leading to the safetyvalve 33. Similarly, fuel is adapted to flow through the valve seat 101into the passage means 102 leading to the controlled pilot burner 28 tocause the resulting flame 34 thereof to open the valve member 37 of thesafety valve means 33 so that fuel can be supplied to the main ovenburner 22.

Since the degree of movement of the valve member 121 away from the valveseats 100 and 101 is related to the temperature setting of the controlknob 82 as illus trated in FIGURES l115, the sensing bulb 112 senses theincrease in temperature of the oven 21 and causes the bellowsconstruction to expand and move the shaft 114 to the left whereby thevalve member 121 moves to left with the shaft 114 toward the valve seats100 and 101, under the influence of the spring 122 maintaining the valvemember 121 against the disc 119, the shaft 114 moving axially relativeto the stem 61.

When the temperature of the oven 21 reaches the temperature selected bythe control knob 82, the bellows construction 105 has expanded to such adegree that the shaft 114 has moved the valve member 121 to the leftagainst the valve seats 100 and 101 whereby the flow of fuel to thecontrolled pilot burner 28 is termianted so that the flame 34 ceases toexist and causes the safety valve 33 to close the valve member 37 in themanner previously described. In this manner, no fuel can flow to themain oven burner 22. After the valve member 121 is seated, furtherexpansion of the bellows construction 105 causes the shaft 114 to moveto the left relative to the seated valve member 121 to provideovertemperature protection.

When the temperature bulb 112 in the oven 21 senses that the temperatureof the oven 21 has fallen below the selected temperature, the bellowsconstruction 105 has collapsed to such a degree that the shaft 114is'moved to the right so that the disc 119 can again contact the valvemember 121 to move the same away from the valve seats 100 and 101 sothat fuel can again flow to the pilot burner 28 and through the mainpassage means 32.

However, it has been found that when the valve member 121 initiallyopens, suflicient fuel is supplied by' the passage means 102 to thepilot burner 28 to cause the flame 34 thereof to open the valve member37 of the safety valve means 33 before the valve member 121 suppliessufficient fuel to the passage means 32 to be fully ignited at the mainoven burner 22.

Therefore, the valve construction 29vis so constructed and arranged thatthe valve member 121 supplies sufficient fuel to the passage means 32 tocause ignition at the main oven burner 22 upon the initial opening ofthe valve means 121 before a sufiicient quantity of fuel is supplied tothe pilot burner 28 to cause the flame 34 thereof.

In particular, reference is made to FIGURES 5, 6 and 7 wherein aleaf-type spring 129 has the shank portion 130 frictionally disposed ina bore 131 formed in the housing 51 and disposed olfset relative to thecenter of the valve member 121 for a purpose hereinafter described, thespring 129 having a reversed turned end portion 132 provided with a capof epoxy resin 1 33' or the like, which,

will bear. against the valve member 121.

The spring-129 is so constructed and arranged, that a the end 133thereof normally extends beyond the valve seats 100 and 101 in themanner illustrated in'FIGURE 7 so that when the valve member 121 isbeing moved to, its closed position, the spring 129 engages the valvemerng ber 121 and cocks the sameon the shaft 114 in such a" mannenthatthe valve member 121 first seats againstonly a portion of the valveseat7100 as illustrated in FIGURE 7 before the valve member 121is fully"seated against,

the valve seats 100 and ltllin the manner illustrated in FIGURE 2. .r er V I, V a i V ture, such as between 140 F. and 325 F., the knob 82 ismoved to the ,dresired temperature, such as, 170 F., wherebythe, recess95- of the valve member 56 interconnects the inlet 30"with the bore 58of the valve member 56 while t'he valvelmemberl56 .closes off thecontrolled pilot bypass means 104 as illustrated by FIGURES 12 and 13.The rotational. movementof thevalve member 56 to the temperature settingof 170 F...also causes rota,-

tional movement of the shaft 114 in'the above manner whereby the valvemember 121 is moved away from the valve seats 1% and 101 to cause fuelto flow to themain passage means 32 and to .the controlled pilotburner28.

Preferably, the spring 129 isdisposed 9O out of phase with the internalvalve seat 101. However, it is to be understood that the spring'means129'c ould be disposed inany desired rotational position relative to thevalve seat 101 that would provide the desiredresults of this invention.

Therefore, when the valve member 121 is fully seated again-st the valveseats 100 and 101 and the sensing bulb 112 senses that thetemperature ofthe .oven 21 is belowr the selected'temperature, thebellows-construction 105 100 and 101.

' However, since the spring ,129 is offset relative to the center of thevalve member .121, the spring me'ans -129.

causes the valve member 121 tobegin to cock on the shaft '114 so-that aportion of the valve seat 100isthe first to open at a. po-intspaced fromthe valvese'at 101 as illustrated in FIGURE 7. p V I In this manner,sufficient fuel flows out of the partially As long as the: valve member121 is open, a flame 34 valve'seats'. 100 ;and 101 toi terminate thesupply of fuel to'the controlled pilot burner 28'wher'eby the flame 34 r7 ceases to exist and the safety valve means 33 closes to prebegins tocollapse to move-the shaft 114,"and thus, the a valve member 121 to theright. away'from the valveseats 7 opened valveseat 100 to thepas'sagemeans'32 to pro! I vide 'a proper amount of fuel for ignition atthe main ove'n burner 22 before a suflicierit amount of fuel is allowedto pass through the valve seat 101 to cause a'fiarne 34 at thecontrolled pilot burner 28.

Thus, each time the valve member 121 jopens, a sufficientamount offuelis present at the safety valve 33' to cause ignition at the main.oven'burner 22 when a flame 34 appears at the controlled pilot burner-28 which 7 opens the safety valve 33.- V Y j V The operation ofthe fuelcontrol system20 of this invention will now be described. v When thecontrol system 20 of this invention has been initially installed, theheight of the flame 34 of the controlled pilot burner 28 can beregulated in the following manner. V As illustrated in FIGURE 12, the,control knob 82 is rotated to the dot 134 by first; depressing the knob82 T to clear the locking tab means 87 of the drivering 84 from theslots 88 of "the cover member 72' inrthe manner previously described.

Whenthe control knob' 82 is rotated to the dot i134 illustrated inFIGURE 12, the valve member. 56 is rotated in the manner illustratedjinFIGURE l2,'whereby the recess 9 5,o-f the valve member 56 interconnects.the

inlet withthe bore 58' thereof and interconnectsthe bore 58 with thebypass 'meansj104 by the recess 98 so that fuel can be supplied to thecontrolled pilot'burner' 28"independently'of the position of' the vvalvemember "described.

vent fuel to flow to the main ovenburner 22.

I Subsequently, when the temperature. of the oven 21 has fallen belowthe selected temperature, thebellows 105 has eollapsed to such a degreethat the. shaftf114moves to the ,right and moves thevalve member 121'away-from'the valve seats-100 and 101 topermitaflame- 34 to exist atthe controlled pilot burner 28 and open the valve means 33aso that fuelwill flow to the mainoven burner 22 to be ignited and heat the oven21. J

Thus, the valve member 121 cycles between the opened and closedpositions thereof in response to the temperature of'the oven 21 to' turnon andolfthernain oven burn- 7 er 22 so thatthetemperature ;of the oven21 is maintained at the selectedlow temperature, the valve member121'when'moving from the 'close'd'p'os'i-tion to the open position thereofalways assuring thatZa sufficient amount offuelis suppliedby the passagemeans 3210 be ignited at "the main oven burner-22 when the flame 34appears at the'control pilot burner 28 in the manner previouslyTherefore; it Ican beseen tlrat the .fuel'control system 20 ofthisinvention'is readilyadapted to maintain the temperature'of the oven 21at a low warming and nonc-ooking temperature while still only utilizingthe main oven'burner' 22 of the oven 21. t

Should it bedesired-to utilize the oven 21 ata conventional cookingtemperature, such as between325 F. and

'550 'F., the control knob 82 is rotated in a counterclockwise directiontothe selected temperature, such as 500 'F. as illustrated in FIGURE 14.Withrthe control knob '82-disposed in the position illustrated in FIGURE14, not only does'the valve member '56 interconnect the inlet 30 withthe bore 58thereof by the recess 95, but the valve member, 56 alsointerconnects the bore 58.015 the valve member 56 Withjthe controlledpilot bypass passage .rne ans;104 by the recess 9930111211 :the flame,34 will always-appeartat the :controlled pilot burner 28'when'the'ternperature setting of the oven'21 is between 325 F. and 550F. in the embodiment of the 121, the fuel issuing from thecontrolledpilotburner '28 being ignited by the standby pilot burner 24.

Should the flame 34 at the controlled pilot burner 28 need adjustment,an adjusting memberrl3 5, FIGURE 2,

is rotated in the proper direction to'cause the passage means 102 inthe'housing 51 to supply a sufiicient amount of fuel to the controlledpilot burner 28 to provide the ,theoven 21, at a'low warming andnon-cooking'temperaa control system 20 illustrated in the drawingregardless of the position of the thermostatically controlled valvemember 121. V V

Thus,iat this high temperature setting, the safety. valve 33 is always.opened because a flarnef34 always appears at' the controlled pilotburner28 whereby the valve 121 merely throttles the'rflow of fuel to the mainoven burner 22 in response to thetemperature of the oven 21.

Therefore, it can be seen that the fuel control system 20 of thisinvention is notonlyradaptcd to maintainan oven 'or the like at arelatively low warming and noncooking tenrperature'with a single mainoven burner, but

is also adaptedito maintain theo-ven at a selected high 9 cookingtemperature utilizing the same main oven burner, features heretoforeunknown in fuel control systems for domestic gas-fired range ovens andthe like,

When the fuel control system is first incorporated in an oven or thelike, calibration of the thermostatic control device is a simpleoperation and is accomplished by placing the temperature sensing bulb112 in a bath having a pre-determined temperature, for example 400 F.

The control knob 82 is rotated counterclockwise to the 400 F. mark onthe dial thereof.

With the insert 83 removed from the control knob 82, a screw driver orthe like is inserted through the control knob 82 and is engaged in thebifurcated end 136 of the stem 61. The adjusting stem 61 is axiallypushed to the right to thereby release the rotational drive between thevalve member 56 and the stem 61 so that the adjusting stem 61' can berotated in either a clockwise or counterclockwise directionindependently of the valve 56 to cause the valve member 121 to bedisposed in light contact with the valve seat 100.

Without any further rotation, the screw driver is released from theadjusting stem 61 to thereby cause the adjusting stem 61 and valvemember 56 to be again placed in rotational drive whereby the control isaccurately calibrated.

If the thermostatic control device of this invention is installed on arange, calibration thereof is easily accomplished by removing the insert83 from the control knob 82. Thereafter, a suitable thermometer isplaced in the center of the oven 21 and the control knob 82 is rotatedcounterclockwise to a predetermined temperature, for example 400 F. Thecontrol system is then allowed sufficient time to level out and the oventemperature on the thermometer is noticed. Thereafter, a screw driver isthen inserted through the control knob 82 and operatively engaged in thebifurcated end 13 6 of the adjusting stem 61. With the screw driver soengaged, the adjusting stem 61 is depressed to the right out of itsrotational drive with the valve member 56. Subsequently, with the screwdriver held so as to prevent rotation of the adjusting stem 61, thecontrol knob 82 is rotated clockwise or counterclockwise to thetemperature setting indicated by the thermometer disposed in the oven21. The screw driver is then disengaged from the adjusting stem 61 in anon-rotational manner whereby the insert 83 can be replaced in thecontrol knob 82 to complete the calibration procedure.

Another calibration can \be accomplished by the valve construction 29after the fuel control system 20 has been installed on a range or thelike.

In particular, a suitable thermometer is placed in the center of theoven 21 and the control knob 82 is rotated counterclockwise to apredetermined temperature, for example, 400 F. The control system isthen allowed sufficient time to level out and the oven temperature onthe thermometer is noticed. If there is mis-calibration, the controlknob 82 and sleeve 79 are removed as a unit from the valve construction29.

Noting the position of the reference indicium 137 on a plate 138 carriedat the end of the adjusting stem 61, a screw driver is engaged in thebifurcated end 136 of the adjusting stem 61 to depress the stem 61 anddisengage rotational drive between the stem 61 and valve member 56. Theadjusting stem 6-1 is then rotated clockwise or counterclockwise, as thecase may be, an angular distance corresponding to the noted number ofdegrees of mis-calibration. For example, if each graduation 139 on theend of the valve member 56 is designed to represent 25 F. temperaturevariation and the noted mis-calibration is also 25 F., the adjustingstem 61 is rotated an angular distance of one fixed graduation 139 inrelation to the reference indicium 137 of the plate 1-38. The screwdriver is then disengaged in a non-rotational manner and the controlknob 82 and sleeve 79 are replaced to complete the calibration procedureTherefore, it can be seen that an improved valve construction 29 isprovided by this invention which not only readily performs the desiredfunctions for the fuel control system 20 of this invention, but which isalso adapted to readily adjust the calibration thereof so that anaccurate control is provided.

The valve construction 29 can be modified in the manner illustrated inFIGURE 2A to provide a non-cycling oven control, if desired.

In particular, the valve member 121a of the valve construction 29a isprovided with a recess 140 in the region of the 'valve seat 101A wherebythe cavity 55a of the valve construction 2% is always in communicationwith the passage means 102a thereof, regardless of whether the valvemember 1211a. is fully seated against the valve seat a as illustrated inFIGURE 2A.

In this manner, fuel is continuously supplied to the controlled pilotburner 28 so that the resulting continuous flame 34 thereof keeps thevalve means 33 in an open position when the control knob 82 is in an onposition thereof, regardless of the position of the thermostaticallycontrolled valve member 12 1a.

When it is desired to utilize the main oven burner 22 for broiling, thecontrol knob 82 is rotated to the position illustrated in FIGURE 15whereby the valve member 56 continues to interconnect the inlet 30 withthe bore 58 of the valve member and closes off communication between thebore 58 and the controlled pilot bypass means 104.

However, it has been found that when the valve member 56 is rotated tothe broil position thereof, the shaft 114 has moved the valve member 121away from the valve seats 100 and 101 such a distance that the valvemember 121 will not close against the valve seats 100 and 101 during thebroiling operation of the oven 21.

Therefore, fuel is continuously supplied to the controlled pilot burner28 by the opened valve seat 101 during the broil setting of the controlknob 82 whereby the flame 34 of the controlled pilot burner maintainsthe valve means 33 in the opened position so that fuel passing throughthe continuously opened valve seat 100 can be continuously supplied tothe main oven burner 22 for broiling purposes.

While the form of the invention now preferred has been disclosed asrequired by the statutes, other forms may be used, all coming within thescope of the claims which follow.

What is claimed is:

1. In combination, a main burner, a source of fuel, main passage meansinterconnecting said source of fuel to said main burner, a pilot burner,ignition means for said burners, a first valve means in said mainpassage means for controlling the flow of fuel to said main burner,means responsive to a flame at said pilot burner to open said firstvalve means, a valve construction in said main passage means upstreamfrom said first valve means, said valve construction having a firstvalve seat for interconnecting said source of fuel to said first valvemeans and having a second valve seat inside said first valve seat forinterconnecting said source of fuel to passage means leading to saidpilot burner, a valve member carried by said housing for opening andclosing said valve seats, spring means carried by said housing andextending beyond said valve seats to engage said valve member beforesaid valve member seats against said valve seats, said spring meansbeing offset relative to the center of said valve member to cause saidvalve member to cock as it nears said second valve seat and to initiallyengage only a portion of said second valve seat before it completelycloses said valve seats so that sufficient fuel is adapted to besupplied to said main burner to have full ignition thereof before aflame appears at said pilot burner.

2. In combination, a housing having a valve seat, a valve member carriedby said housing for opening and valve seat and to said first valve seat.

controls movement of said valve member I it closing said valve seat, andspring means carried by said housing and tending to extend-beyond saidvalve seat 'to, engage said valve member before'said valve member seatsagainst said valve seat, saidrspringgmeans being 'oifset relative to thecenter of said valve'member to I, cause said valve member'to cock onlyas it nears said valve seat and to initially engage only a portion ofsaid valve seat before it completelyseals closed said valveseat.

3.. In combination, a housing having a first valve seat;

and having a second valve seat encompassing said first valve seat, avalve member carried by said housing for opening and closing said .valveseats, and spring means.

carried by said housing and tending to extend beyond said valve seats toengage said valve member before said valve member seats againstsaidvalve seats, said. spring] means being oifset relative. to the center ofsaidvalve said second valve seat and to initially engage only a portionof'said second valve seat before it completely seals closed said valveseats.

valve seats are disposed in the same plane.

5. A combination as set forth in claim '3 'wherein said second valveseat is substantially annular and said first valve seat is substantiallyannular. and is oifset relative to the center of said second valve seat,and wherein said spring means is offset relative to the center of s aidsecond 6. A'c'ombination as set' forth' in claim 3 wherein tem peratureresponsive meansis carried by said housing and relative to said valveseats.

a temperature responsive V .valve member relative'to said valve seats.

of fuel, main passage means interconnecting said source of fuel tosaidmain burner, a pilot burner, ignition means for said burners,-afirst valve means in said main passage means for controlling the flow offuel to said main burner,

' meansresponsive to a flame at said pilot'burner to open said firstvalve means, a valve construction in said main passage meansupstreamfrom said first valve means, said valve construction having afirstvalve seat for in- 'terconnectingsaid source of fuel'to said firstvalve means member to canse'saidvalve member to cock as it :nearsr 20 4.A combination as set'forth in claim 3 whereinsaid said second valve seatis disposed inside said first valve 7. In a fuel control system, .avalve construction having a first valve seat and a second valve seat forrespectively interconnecting a source of fuel to difierent burner means,a valve member for opening and closing said valve seats, and means formoving and initially tilting said valve I 7 wherein A and havinga secondvalve seat for interconnecting said sourceof 'fuel'to passage meansleading to said pilot burner, a valve member for opening and closingsaid valve seats, and means formoving and initially tilting said'valvemember relative to said seats to initially open said first valve seat topermit suificient fuel to. flow to said mainlburner to have fullignition thereof before said second valve seat-is opened sufliciently topermit ignition at its respective burner means.

12. A'fuel control system according to claim 11 wherein seat. I I

13. A fuel control system according to claim 11 wherein said valve seatsare inv the same plane.

14. A fuel control system according to claim 11 where- "in temperatureresponsive means controls movement of said valve member relative to saidvalve seats.

References: Cited in the file of this patent v -UNITED STATES PATENTS'Bell et a1; July 7, 1891 1,576,086 Browne Mar. 9, 1926 1,704,807 ONealMar. 12, 1929 1,705,787 I Shuell et a1. n Mar. 19, 1929. 1,842,335 f TePas a Jan. 19, 1932 1,950,120 McKee 'Mar. 6, 1934 2,069,069 Horton Jan.26, 1937 2,106,929 McClure Feb. 1, 1938 f 2,505,455 Andersson Apr.25,1950 2,509,679 Evans May 30,1950 2,898,048 Stucka Aug. 4, 19592,994,755 r Hildenbrandt et a1. Aug. 1, 1961 3,065,913 Holzboog et a1NOV. 27, '1962 FOREIGN PATENTS France May 15,,

1. IN COMBINATION, A MAIN BURNER, A SOURCE OF FUEL, MAIN PASSAGE MEANSINTERCONNECTING SAID SOURCE OF FUEL TO SAID MAIN BURNER, A PILOT BURNER,IGNITION MEANS FOR SAID BURNERS, A FIRST VALVE MEANS IN SAID MAINPASSAGE MEANS FOR CONTROLLING THE FLOW OF FUEL TO SAID MAIN BURNER,MEANS RESPONSIVE TO A FLAME AT SAID PILOT BURNER TO OPEN SAID FIRSTVALVE MEANS, A VALVE CONSTRUCTION IN SAID MAIN PASSAGE MEANS UPSTREAMFROM SAID FIRST VALVE MEANS, SAID VALVE CONSTRUCTION HAVING A FIRSTVALVE SEAT FOR INTERCONNECTING SAID SOURCE OF FUEL TO SAID FIRST VALVEMEANS AND HAVING A SECOND VALVE SEAT INSIDE SAID FIRST VALVE MEANS FORINTERCONNECTING SAID SOURCE OF FUEL TO PASSAGE MEANS LEADING TO SAIDPILOT BURNER, A VALVE MEMBER CARRIED BY SAID HOUSING FOR OPENING ANDCLOSING SAID VALVE SEATS, SPRING MEANS CARRIED BY SAID HOUSING ANDEXTENDING BEYOND SAID VALVE SEATS TO ENGAGE SAID VALVE MEMBER BEFORESAID VALVE MEMBER SEATS AGAINST SAID VALVE SEATS, SAID SPRING MEANSBEING OFFSET RELATIVE TO THE CENTER OF SAID VALVE MEMBER TO CAUSE SAIDVALVE MEMBER TO COCK